Pipe cutting machine

ABSTRACT

The principle of severing tubular members such as cast-iron pipe by constricting a flexible cutting element looped about the member so as to force the element through the walls thereof, is incorporated into a high-volume, production line machine. Holding structure on the machine yieldably maintains the cutting element in an open loop at all times, subject only to the loop being expanded and constricted during the cutting cycle, whereby the members being processed may be rapidly inserted into and removed from the cutting element. High efficiency power apparatus is associated with the cutting element to effect the powered expansion and constriction thereof during the operating cycle.

United States Patent Bivona et a1.

1 Jan. 28, 1975 1 PIPE CUTTING MACHINE 22 Filed: Aug. 27, 1973 21 Appl. No.: 391,935

[56] References Cited UNlTED STATES PATENTS 2,825,967 3/1958 Wheeler 30/101 X 3,456,856 7/1969 Berberian .1 225/103 FORElGN PATENTS OR APPLICATIONS 694,216 9/1964 Canada 30/100 Primary Examiner-Andrew R. Juhasz Assistant ExuminerLcon Gilden Attorney, Agent, or FirmSchmidt, Johnson, Hovey & Williams 1 1 ABSTRACT The principle of severing tubular members such as cast-iron pipe by constricting a flexible cutting element looped about the member so as to force the element through the walls thereof, is incorporated into a high-volume, production line machine. Holding structure on the machine yieldably maintains the cutting element in an open loop at all times, subject only to the loop being expanded and constricted during the cutting cycle, whereby the members being processed may be rapidly inserted into and removed from the cutting element. High efficiency power apparatus is associated with the cutting element to effect the powered expansion and constriction thereof during the operating cycle.

PIPE CUTTING MACHINE This invention relates to a special cutting or severing action utilized where certain tubular members such as, for example, cast-iron soil pipe or plastic tubes, are to be severed. The inherent nature of such members dictates that, for the most part, they be severed not by a sawing action or a chopping movement, but rather by a flexible cutting element having a number of sharp discs thereon that is looped about the member and forced through the walls thereof as the loop is tightened, thus destroying the molecular structure of the member so as to part or fracture the same. In the case of cast-iron soil pipe, this manner of severance eliminated rapid dulling of the cutting tool that occurs when other severing methods are employed.

This principle of using a flexible cutting element that is looped about and forced through the tubular member to sever the same is not new, and accordingly, does not per se form the subject of the present invention. However, the principle has not heretofore been successfully incorporated into a high-volume, production line machine capable of severing the members at a rapid rate with a minimum of operator involvement and setup time between successive cuts. To date, the bulk of devices employing the constricting loop principle have been highly portable units used to sever the pipe in situ within an open trench or the like for purposes of repair.

Accordingly, it is one important object of the present invention to provide a high-volume, production line machine employing the constricting loop principle above described for severing tubular members requiring such special treatment, e.g., cast-iron pipe.

In accordance with the foregoing, another important object is the provision of a production line machine as aforesaid having a flexible cutting element that is constantly maintained in an open, constrictable loop so that manual attachment and detachment of one end of the element each time a cut is to be made is not required, thus permitting the member to be quickly and easily inserted into and withdrawn from the loop before and after constricting the same.

An additional important object of this invention is to provide a machine as aforesaid which is capable of rapidly severing successive portions from tubular members of substantially the same size presented thereto, yet which may be readily adapted for accepting members ofa new size when one production run of the first sized members has been completed.

A further important object is to provide such a machine having high mechanical advantage power apparatus associated with the looped cutting element for constricting and expanding the same in a manner to provide relatively rapid, yet powerful severance of the members by the element.

Yet another important object of this invention is to provide a machine having the capabilities set forth in the foregoing objects, yet which is not so unduly massive that it cannot be readily transported to a construction site where a large number of lengths of pipe are required such as to complete the plumbing phases of the construction project.

In the drawings:

FIG. 1 is a side elevational view of a machine embodying the principles of the present invention, the looped cutting element thereof being shown in its expanded condition for receiving or discharging a tubular member;

FIG. 2 is a fragmentary, side elevational view of the machine similar to FIG. I but showing the cutting element in a constricted condition for severing the member;

FIG. 3 is a fragmentary, vertical cross-sectional view of the machine taken along line 3--3 of FIG. 1',

FIG. 4 is an enlarged, fragmentary elevational view of the right end of the element illustrating the manner in which it is secured to the proximal jaw of the machine;

FIG. 5 is a fragmentary, cross-sectional view of the power apparatus of the machine taken along line 5-5 of FIG. 1;

FIG. 6 is a horizontal, cross-sectional view of the machine taken along line 66 of FIG. 1;

FIG. 7 is an enlarged, fragmentary cross-sectional view of the cutting element taken along line 77 of FIG. 1; and

FIG. 8 is a largely schematic illustration on a reduced scale of a suggested arrangement of table components and the like usable in association with the present machine for highvolume, production line severance.

The machine 10 has a base 12, of generally open framework construction, provided with a flat, heavy top or table 14 that has an elongated opening 16 therein (FIG. 6) through which a pair of generally uprightjaws 18 and 20 extend. The jaws l8 and 20 are basically triangular in configuration having a common horizontal pivot 22 through a pair of blocks 24 disposed on opposite lateral sides of opening 16. The pivot 22 is located at one corner of each jaw 18 and 20 so that the remaining corners on opposite jaws l8 and 20 swing toward and away from one another in response to relative movement between the jaws l8 and 20.

The upper corners of the jaws 18 and 20 have opposite ends of an elongated, flexible, link-type cutting element 26 secured thereto in the manner illustrated in detail in FIG. 4. Each end link 28 is secured to its proximal jaw 18 or 20 by virtue of a removable pin 30 extending through aligned holes 32 and 34 in the jaw 18 or 20 and the link 28 respectively. The element 26 is in this manner rendered relatively permanently attached to the jaws l8 and 20 in the sense that it remains in place during successive cutting operations on tubular members of substantially the same size, yet the removability of each pin 30 renders the element 26 detachable from jaws l8 and 20 to the extent necessary to replace element 26 with a new element of longer or shorter length so as to accommodate a new production run of tubular members having different sizes than those previously severed with element 26.

As is conventional, the element 26 is provided with a series of hardened cutting discs 36 along the length of element 26, each disc .36 being rotatably carried in element 26 by a pivot pin 38, and each having its outer periphery exposed so as to present a series of arcuate cutting surfaces in the interior of the loop formed by element 26.

The loop formed by element 26 is continuously maintained in an open condition by virtue of special holding structure 40 on table 14. Structure 40 includes a generally cylindrical support 42 circumscribing the looped element 26 in radially spaced relationship thereto, and also includes three circumferentially spaced, radially extending spring devices 44 that yieldably interconnect support 42 and element 26. Although the devices 44 vary slightly in size, they are essentially identical to one another, each including a tension spring 46 secured at its outer end to the support 42 via a tension adjusting bolt and nut assembly 48 and secured at its inner end to the element 26 in the manner illustrated in FIG. 7. As therein illustrated (as well as in FIGS. 1 and 2), an inverted rivet 50, hooked to theinner end of spring 46, is passed through a crosspiece 52 that extends between two sets of normally radially extending, circumferentially spaced apart connecting links 54 attached to opposite ends of crosspiece 52. By virtue of the yieldable connection thus created between the element 26 and the support 42, the element 26 is maintained in an open loop configuration regardless of whether the same is expanded to its receiving condition of FIG. 1 or constricted to its severing condition of FIG. 2.

The entire holding structure 40 is rendered removable by virtue of a pair of uprights 56 welded to opposite sides of support 42 that have their lowermost ends removably received within elongated slots 58 (FIG. 6) extending transversely to opening 16 at opposite ends thereof. An L-shaped mounting lug 60 on each upright 56 has a mounting screw 62 extending vertically therethrough and threaded into the table 14 for releasably fastening the support 42 against the table 14.

The jaws I8 and 20, and hence element 26, are operated by power apparatus denoted broadly by the numeral 64 and disposed below table 14 within the confines of the framework construction of base 12. A special arm 66 has, at one end thereof, a pair of spacedapart connections 68 and 70 with the lower corners of the jaws 18 and 20 respectively, the connection 68 being double-jointed with jaw 18 while the connection 70 is single-jointed with jaw 20. As illustrated, the connection 68 is rendered double-jointed by virtue of an intermediate link 72 between arm 66 and jaw 18, there being one joint 74 at the normally uppermost end of link 72 where the latter is pivotally attached to jaw 18, and a second joint 76 at the normally lowermost end of link 72 where the latter pivotally joins arm 66. A vertically extending race 78 (shown in detail in FIG. limits the joint 76 to solely vertical movement during swinging of arm 66 whereby to reciprocate the jaws I8 and about pivot 22 when the arm 66 is swung in opposite directions. Such swinging of arm 66 may be effected through a hydraulic or pneumatic piston and cylinder assembly 80 having its stem 82 pivotally attached to the end of arm 66 opposite the connections 68 and 70.

As shown in detail in FIG. 5, the arm 66 is bifurcated at joint 76 so as to receive the link 72 between the opposed furcations 66a and 66b. A common pin 84 joins the furcations 66a and 66b with link 72 and carries a pair of rollers 86 at its opposite ends for movement within opposed trackways 88 of race 78.

OPERATION FIG. 8 illustrates schematically one manner in which the machine 10 of the present invention can be utilized in a production line operation. FIG. 8 shows that, in conjunction with the machine 10, a feed table 90 and a discharge table 92 may be used in order to streamline the steps of introducing members to machine 10 and removing them therefrom after severance. As illustrated, it is contemplated that a supply of tubular memhers such as pipes 94 may be gravity fed by table 90 to releasable stop mechanism 96 for individual release therefrom to an upright guide 98 in horizontal registration with the element 26 of machine 10. The lowermost pipe 94a may then be pushed forwardly into the expanded loop of element 26 until striking a variable stop 100 on discharge table 92. After severance, the severed portion 94b may gravitate from stop 100 along inclined discharge table 92 for collection at a remote point.

When the machine 10 receives the lowermost pipe 94a from feed table 90, the operating components of machine 10 are in the condition illustrated in FIG. I wherein the element 26 is expanded to its fullest extent. At this time, the connection 68 of arm 66 with jaw 18 is almost in a straight line condition with joint 76 at the lower limit of race 78. Then, after the pipe 94a has been inserted into the element 26 and butted against stop 100 on table 92, suitable actuating mechanism (not shown) may be activated to cause the stem 82 of piston and cylinder assembly to be withdrawn so as to pull the lower end of arm 66 in a counterclockwise direction from the condition in FIG. 1 toward that of FIG. 2. This causes joint 76 to rise in race 78 thus forcing the lower corners of jaws l8 and 20 apart as illustrated in FIG. 2, and bringing the upper corners thereof together so as to constrict the looped element 26. Hence, the cutting discs 36 of element 26 are progressively forced into and through the walls of pipe 94a so as to destroy the molecular structure thereof and simply part or fracture the pipe 94a with great force. Then, the piston and cylinder assembly 80 is actuated in the opposite direction to extend stem 82, thereby opening jaws 18 and 20 to expand element 26 to its FIG. I condition.

It is important to recognize that, during this powered severance of the pipe 94a, the spring devices 44 have maintained the element 26 in an open-loop configuration at all times, subject only to the loop being constricted from its expanded condition of FIG. 1 by the power apparatus 64 in conjunction with jaws l8 and 20. Therefore, prior to the application of power to the jaws 18 and 20 when machine 10 is in the condition of FIG. 1, the devices 44 maintain element 26 fully expanded so as to permit ready insertion of the pipe 94a into and through the same against stop 100. Then, during the severing action itself, the devices 44, by virtue of their inherent yieldable nature, permit the element 26 to constrict in its forced movement through the walls of pipe 94a. Once the severance has been completed and pipe 94a is no longer within element 26, the latter is still maintained in an open condition by devices 44 and, upon actuation ofjaws l8 and 20 to expand element 26, the latter is ready to receive the next portion of pipe 94a to be severed.

Cutting of a large supply of pipes of substantially the same diameter can thus proceed at a relatively rapid rate with a minimum of operator attention and effort. While in the past it was necessary to disconnect one end of a cutting element after each severing stroke, insert a section of pipe, and then reconnect the element before beginning the actual severing stroke, it is now possible, with machine 10, to completely eliminate these tim e-consuming and thus costly steps in the severing operation. It is only necessary to ascertain that the element 26 has been expanded by jaws I8, 20 and spring devices 44 a sufficient extent to allow the introduction of the next section of pipe, whereupon the power stroke of machine 10 can begin. In this manner, a very large volume of pipe can be cut to the desired length in a fraction of the time required with prior portable devices.

While the machine is especially designed for highvolume, production line operation such as necessary at a construction site where a large number of pipes of the same diameter and length must be prepared, the machine 10 is designed to permit relatively rapid setup for a new production run of pipes having different diameiers than those previously severed. To this end, by removing the mounting screws 62 and forcing the retaining pins 30 of element 26 out of the jaws l8 and 20, the entire holding structure 40 and element 26 may be removed from the machine 10 and replaced with substitute parts including a new cutting element having the appropriate length to accommodate the new sizes of pipes to be severed. When the new parts are placed upon the table 14 it is but necessary to replace the mounting screws 62 and the retaining pins 30, whereupon operation can once again resume.

lt is also to be noted that the special power apparatus 64 utilized for operating jaws l8 and is capable of obtaining a high mechanical advantage so as to exert a great force against the pipe being severed through the cutting discs 36. Moreover, the sturdy construction of apparatus 64 renders the machine 10 virtually maintenance-free for long-lived, reliable operation.

An additional important consideration not heretofore emphasized, is the fact that the machine 10 operates with a high degree of safety in spite of the great force exerted by the working components of machine 10 during the severing action. In this respect, the cylindrical support 42 serves not only as a means for mounting the spring devices 44, but also as a partial protection shroud about the point at which great force is applied to the member being severed. Thus, in the unlikely event that the element 26 should fail during the power stroke of apparatus 64, the support 42 shields the operator to a large extent from such potentially dangerous occurrence.

Having thus described the invention, what is claimed as new and desired to be secured by letters is:

l. A machine for severing tubular members comprising:

a base;

a pair ofjaws mounted on said base for relative reciprocable movement toward and away from one another;

an elongated, flexible cutting element;

means securing one end of said element to one of said jaws and the opposite end to the other of said jaws;

power apparatus operably coupled with said jaws for forcing said element through the walls ofa member encircled by the element when said apparatus is actuated to thereby sever the member; and

structure on said base resiliently pulling outwardly on said element to hold the same in a non-collapsed, open loop prior to, during, and after actuation of said apparatus,

said jaws being operable to constrict said loop against the resistance of said structure during relative movement in one direction for severing the memher and being operable to expand said loop during relative movement in the opposite direction, whereby to permit rapid insertion and removal of the member into and out of the loop.

2. A machine as claimed in claim 1, wherein said structure includes a rigid support and means yieldably interconnecting said support and the looped element.

3. A machine as claimed in claim 2. wherein said support circumscribes said element in radially spaced relation thereto, said yieldable means including a plurality of circumferentially spaced spring devices between the element and the support.

4. A machine as claimed in claim l, wherein said structure is provided with means removably attaching the same to said base for substitution of a replacement structure on the base having an element of a different length than the first-mentioned element, said securing means being releasable.

5. A machine as claimed in claim 4, wherein said securing means for each jaw includes a removable pin extending through the jaw and the proximal end of the element.

6. A machine as claimed in claim 1, wherein said jaws are swingably mounted on said base, said apparatus including an elongated, swingable arm having a pair of spaced connections with said jaws'adjacent one end of said arm, one of said connections being double-jointed for reciprocation of said jaws when said arm is swung in opposite directions.

7. A machine as claimed in claim 6, wherein one of said joints is provided with a race for limiting the one joint to a prescribed path of travel during swinging of the arm.

8. A machine as claimed in claim 7, wherein said apparatus further includes a fluid pressure piston and cylinder unit coupled with said arm adjacent the opposite end thereof for actuating the same.

9. A machine for severing tubular members comprising:

a base;

a pair ofjaws mounted on said base for relative reciprocable movement toward and away from one another;

an elongated, flexible cutting element;

means securing one end of said element to one of said jaws and the opposite end to the other of said jaws;

power apparatus operably coupled with said jaws for forcing said element through the walls of a member encircled by the element when saidapparatus is actuated to thereby sever the member; and

structure on said base holding said elements in a noncollapsed, open loop prior to, during, and after actuation of said apparatus,

said jaws being operable to constrict said loop during relative movement in one direction for severing the member and being operable to expand said loop during relative movement in the opposite direction for rapid insertion and removal of the member into and out of the loop,

said structure including a rigid support and means yieldably interconnecting said support and the looped element,

said support circumscribing said element in radially spaced relation thereto,

said yieldable means including a plurality of circumferentially spaced spring devices between the element and the support.

10. A machine for severing tubular members comprising:

a base;

a pair ofjaws mounted on said base for relative reciprocable movement toward and away from one another;

an elongated, flexible cutting element;

means securing one end of said element to one of said jaws and the opposite end to the other of said jaws;

power apparatus operably coupled with said jaws for forcing said element through the walls ofa member encircled by the element when said apparatus is actuated to thereby sever the member; and

structure of said base holding said element in a noncollapsed, open loop prior to, during, and after actuation of said apparatus,

said jaws being operable to constrict said loop during relative movement in one direction for severing the member and being operable to expand said loop during relative movement in the opposite direction for rapid insertion and removal of the member into and out of the loop,

said jaws being swingably mounted on said base, said of said joints is provided with a race for limiting the one joint to a prescribed path of travel during swinging of the arm. I 

1. A machine for severing tubular members comprising: a base; a pair of jaws mounted on said base for relative reciprocable movement toward and away from one another; an elongated, flexible cutting element; means securing one end of said element to one of said jaws and the opposite end to the other of said jaws; power apparatus operably coupled with said jaws for forcing said element through the walls of a member encircled by the element when said apparatus is actuated to thereby sever the member; and structure on said base resiliently pulling outwardly on said element to hold the same in a non-collapsed, open loop prior to, during, and after actuation of said apparatus, said jaws being operable to constrict said loop against the resistance of said structure during relative movement in one direction for severing the member and being operable to expand said loop during relative movement in the opposite direction, whereby to permit rapid insertion and removal of the member into and out of the loop.
 2. A machine as claimed in claim 1, wherein said structure includes a rigid support and means yieldably interconnecting said support and the looped element.
 3. A machine as claimed in claim 2, wherein said support circumscribes said element in radially spaced relation thereto, said yieldable means including a plurality of circumferentially spaced spring devices between the element and the support.
 4. A machine as claimed in claim 1, wherein said structure is provided with means removably attaching the same to said base for substitution of a replacement structure on the base having an element of a different length than the first-mentioned element, said securing means being releasable.
 5. A machine as claimed in claim 4, wherein said securing means for each jaw includes a removable pin extending through the jaw and the proximal end of the element.
 6. A machine as claimed in claim 1, wherein said jaws are swingably mounted on said base, said apparatus including an elongated, swingable arm having a pair of spaced connections with said jaws adjacent one end of said arm, one of said connections being double-jointed for reciprocation of said jaws when said arm is swung in opposite directions.
 7. A machine as claimed in claim 6, wherein one of said joints is provided with a race for limiting the one joint to a prescribed path of travel during swinging of the arm.
 8. A machine as claimed in claim 7, wherein said apparatus further includes a fluid pressure piston and cylinder unit coupled with said arm adjacent the opposite end thereof for actuating the same.
 9. A machine for severing tubular members comprising: a base; a pair of jaws mounted on said base for relative reciprocable movement toward and away from one another; an elongated, flexible cutting element; means securing one end of said element to one of said jaws and the opposite end to the other of said jaws; power apparatus operably coupled with said jaws for forcing said element through the walls of a member encircled by the element when said apparatus is actuated to thereby sever the member; and structure on said base holding said elements in a non-collapsed, open loop prior to, during, and after actuation of said apparatus, said jaws being operable to constrict said loop during relative movement in one direction for severing the member and being operable to expand said loop during relative movement in the opposite direction for rapid insertion and removal of the member into and out of the loop, said structure including a rigid support and means yieldably interconnecting said support and the looped element, said support circumscribing said element in radially spaced relation thereto, said yieldable means including a plurality of circumferentially spaced spring devices between the element and the support.
 10. A machine for severing tubular members comprising: a base; a pair of jaws mounted on said base for relative reciprocable movement toward and away from one another; an elongated, flexible cutting element; means securing one end of said element to one of said jaws and the opposite end to the other of said jaws; power apparatus operably coupled with said jaws for forcing said element through the walls of a member encircled by the element when said apparatus is actuated to thereby sever the member; and structure of said base holding said element in a non-collapsed, open loop prior to, during, and after actuation of said apparatus, said jaws being operable to constrict said loop during relative movement in one direction for severing the member and being operable to expand said loop during relative movement in the opposite direction for rapid insertion and removal of the member into and out of the loop, said jaws being swingably mounted on said base, said apparatus including an elongated, swingable arm having a pair of spaced connections with said jaws adjacent one end of said arm, one of said connections being double-jointed for reciprocation of said jaws when said arm is swung in opposite directions, said structure including a rigid support about said looped element in radially spaced relation thereto and a plurality of circumferentially spaced spring devices between the support and the element yieldably interconnecting the same.
 11. A machine as claimed in claim 10, wherein one of said joints is provided with a race for limiting the one joint to a prescribed path of travel during swinging of the arm. 